Bubble column



Aug. 25, 1936. R, M, PARSONS 2,052,532

BUBBLE COLUMN ug. 25,l 1936.

R. M. PARSONS BUBBLE COLUMN Filed March 2, 1935 2 Sheets-Sheet 2 www ORNEY Patented Aug.' 25, 1936 PATENT OFFICE I BUBBLE COLUMN Ralph M. Parsons, Mount Vernon, hio, assigner to The Ralph M. Parsons Company, Mount Vernon, Ohio, a corporation of Delaware Application Maren 2, 1935, serial No. 8,990 -s claims. (01.261-114) V This invention relates to bubble columns and more particularly to a new and improved bubble tray for use in oil rening equipment such as fractionating columns. rerun columns or the like.

An object of thev invention is to provide a bubble tray having the maximum useful area.

Another object is to provide a bubble tray having a simplified means of support.

Another object is to provide a bubble tray in which the path' of iiow is controlled with respect to the position of the bubble caps.

' Another object is to provide a bubble towe without external manholes between the bubble trays.

Another object is to provide means for removing side cuts.

Another object 1s to provide a side cut bucket that can be readily attached to any selected bubble tray after the column is assembled.

Another object is to provide a bubble tray that can be assembled from within the tower.

'Various other objects and advantages will be apparent as the nature of the invention is more fully disclosed. I

Although the novel features which are believed to be' characteristic of this invention will be pointed out more particularly in the claims appended hereto, the invention itself will be better understood by referring to the following description, taken in connection with the accompanying drawings, in which certain speciiic embodiments thereof have been setforth for purposes -oi illustration. In the description and in the claims certain specific terms have been used for convenience in referring to various features of the invention but it will be understood that they lare to be interpreted as broadly as the art will permit.

40 In the drawings:

Fig. 1 is a vertical section through a portion of a bubble column illustrating one embodiment of the invention;

l Fig. 2 is a plan view of one of the trays shown in Fig. 1;

Fig. 3 is a section taken on the line 3--3 of Fig. 1:

Fig. 4 isa section taken on the line 4 4 of Fig. 3; and

an improved Fis. 5 is a section taken on the line 6 5 of l Fig. 3.

l The same reference Acharacters denote like parts in the various figures.

The 'present invention provides a bubble tray for \a typical bubble column having a plurality of vertically spaced trays arranged so that the fluid to be fractionated. veither liquid or vapor,

is introduced at an intermediate point in the column. The vapor is caused to bubble upwardly through the liquid on the various trays and the 5 liquid fraction passes downwardly to collect at the bottom of the tower from which it may be removed. The vapor may be removed from the top of the tower or as a side cut from any desired tray. In the operation of this type of i0 tower the temperature becomes progressively lower, passing from the bottom tothe top of the column. Hence, different fractions condense and separate from the vapors in the various trays. Intermediate fractions having any de- 15 sired characteristics can be removed as side cuts from selected points in the column.

The features thus far described are typical of a iractionating or rerun column in an oil cracking plant and are accordingly not set forth here- 20 in in detail.

The drawings illustrate a type of tray that is particularly adapted to large columns. In this form each tray is conveniently made in two4 A halves 55a, 55h, which are joined by anges 66 25 and bolts 61 (Fig. 2). Since the trays are comparatively heavy they may be independently supported in the tower 68 by peripheral flanges 69 attached to said tower as by welding and bolted to said trays. by bolts'10. y 30 Each tray is provided with raised flanges 1i forming bubble openings 12, flanges 13 forming downcomer openings 14, and a iiange 15 forming a center manhole 16. In this embodiment a pair of diametrically opposite downcomer openings 14 35 are provided and the bubble openings 12 are arranged in two staggered concentric rows. The downcomer openings 14 are pear-shaped so asito f occupy the least possible circumferential space. l Bubble caps 80. having radial spacing ribs 8l, are 40 secured to the iianges 1l as by T-sh'aped tie rods 82 which span the openings 12 and extend through the caps to which they are secured by nuts 83.

A manhole cover Y8!! -is provided with anges 85 forming a peripheral recess 86 which seats on the 45 iiange 15. A soft packing 81 may be used to provide a tight seal if desired. The cover 84 may be secured by bolts 90 threaded into bosses 9i formed on said cover and engaging lugs 92 which 5o yseat over downwardly projecting ears 83 formed on vthe tray 55. y Y

' Downcomers s6 are bolted to the bottom of the tray 55 in register with the downcomer openings 'Itl as by means of flanges 85 and bolts 86. The l' downcomers extend to a pointbelow the liquid level on the tray below.

In order to remove a side cut from any desired tray a novel type of bucket is provided which is interchangeable with any downcomer. This bucket is shown as a bucket |00 attached to a downcomer |0| which is shorter than the downcomers 94 by an amount suiiicient to provide clearance for the bucket. The bucket 00 is provided with positioning bosses |02 which rest against the bottom of the downcomer |0| to space the bottom of the bucket therefrom, and with a pair of inner walls |03 of less height than the outer walls |04 and defining openings |05 on opposite sides of the downcomer |00 through which the excess liquid overiiows to the tray below at a point adjacent the downcomer and leads to a tapped hole. |08 in the outer wall of the tower 68. The holes |06 are formed in opposite walls of the bucket |00 so as to provide for right or left hand assembly of the discharge pipe |01. The one which is not used for this purpose may be closed by a plug |09. Suitable holes |08 may be formedv in the tower 68 at all trays if desired and the unused holes may be closed by a suitable plug. This permits the bucket |00 to be mounted on any desired tray with a minimum amount of labor. The bucket is attached to the downcomer |0| by` bolts I I0 which extend through the bottom of the bucket into iianges formed on the downcomers.

In assembling this type of column the trays are lowered in'halves and are bolted together and to the ilanges 69, beginning at the bottom tray.- The workman bolts each tray in place andi stands thereon while bolting the Vnext tray. The bubble Icaps 80 and the manhole covers 84 may be stored on the proper trays until the trays are all in place. The workman then assembles the bubble caps 80 beginning at the top tray and when each tray is finished positions the manhole cover and `secures the same from below, nally leaving from a suitable opening (not shown) at the bottom of the tower. Certain selected trays are provided with side cut buckets |00. f As these trays are reached suitable connections of the pipe |01 are made to the outer wall of the tower.

Thereafter, the column may be entered \from necessary to remove a downcomer 94 and to sub,

stitute a downcomer |00 with the bucket attached thereto. It is obvious that the number and arrangement of bubble openings and of the downcomers may be varied to suit requirements in any particular installation. In the form shown two concentric rows of bubble openings and two diametrically opposite downcomers are associated with each tray. Successive trays are displaced so that liquid received from one downcomer ows over one fourth of the tray to the next set of downcomers.

In operation, the liquid is received on each tray from the downcomers 94 of the tray above and Amay be closedby a suitable cover when the trays rises to a level such that the bottom of the downcomer is sealed thereby. As the anges 1| and 13 are of the same height, the liquid rises above the top of the flanges 1| before it can overflow over the iianges 13 and discharge through the 5 downcomer opening 'i4 to the tray below. The liquid is prevented, however, by the vapors rising .through the openings l2, from overflowing the iianges 1| and passing through said openings 12. As the liquid passes over the tray from one downcomer 94 to the opposite opening 14, it is directed by the flange |5 over the various openings 12 in contact with the vapors which pass upwardly y through said openings and bubble up through the liquid around the caps. 15

As the process proceeds, the vapors accumulate at the top of the column and may be removed While the liquid collects at the bottom of the l column. A side cut may be tapped off from any intermediate tray by substituting a downcomer |0| and its bucket |00 for a downcomer 94 and connecting the discharge pipe |01 to the corresponding tapped hole |08 in the outer wall of the tower.

The number and arrangement of the downcomers and bubble caps ,may be'varied as desired, depending on the operating requirements. The tower may be easily assembled and may be readily entered for inspection or repair. MThe constructionv is such that the side cut buckets may be located at any desired tray after the tower has been assembled and without making any substantial alterations therein. The various parts may be standardized and at the same time the operation may be altered as desired to meet vari,- ous plant requirements.

It isto be noted that the positioning of the manhole in the center and the bubble openings at the outside utilizes the available area to the best advantage. Furthermore, the inactive area vat the periphery is reduced to a minimum.

It is to be understood that a sufficient opening must be provided at the top ofthe tower to permit the trays to be lowered therethrough,which 45 have been assembled. The tower may, for example, be provided with a separate-head which may be attached to the tower in any suitable manner as by welding. Access to the bottom of the tower may be aiorded by a separable bottom vwhich may also be attached in any suitable manner.

' Although certain specic embodiments of the invention have been described for purposes of illustration, it is obvious that various modifications may be made. therein by a person skilled in the art and that the invention is only to be limited in accordance with the scope of the following claims `when interpreted in view of the prior art.

What is claimedis:

1. In combination, a bubble tray, a down,- comer carried thereby through which liquid is discharged, a side cut bucket attached to said downcomer and adapted to receive liquid therefrom, said bucket having spacing lugs adapted to rest against the bottom of said downcomer to provide clearance for the discharge of liquid. having bottom openings outside of said downcomer surrounded by walls over which liquid can overiiow to another tray, and having means to discharge liquid to a point beyond said tray.

. 2. In a bubble tower, in combination, a plurality of spaced bubble trays, a downcomer associated with each tray, certain downcomers extending to a point `below the liquid level on the tray be- 75 low, other downcomers having side cut buckets associated therewith and being interchangeable with said rst downcomers whereby a side cut can be taken from any selected tray after the tower is assembled.

3. In a bubble tower, in combination, a plurality of spaced bubble trays, a downcomer associated with each tray, certain downcomers extending to a point below the liquid level on the tray below, other downcomers having side cut buckets associated therewith and being interchangeable with said first downcomers whereby a side cut can be taken from any selected tray after the tower is assembled, said buckets being secured to said last downcomers, having bottom openings on opposite sides of the downcomers surrounded by walls over which the liquid overows to the tray below, and having a discharge pipe leading to the outside of said tower.

4. In a bubble tower, in combination, a plurality of spaced bubble trays, a downcomer associated with each tray, certain downcomers extending to a point below the liquid level on the tray below, other downcomers havingside cut buckets associated therewith and being interchangeable with said first downcomers whereby a side cut can be taken from any selected tray after the tower is assembled, said buckets having overow means discharging to the tray below adjacent the downcomer, and having a discharge pipe leading to the outside of the tower. I

5. In a bubble tower, in combination, a plurality of spaced bubble trays, each tray having a central manhole and bubble openings disposed therearound, a raised circular ange around said manhole to coniine the liquid to the circular path around said bubble openings, a manhole cover seated on said iiange and means to secure said cover from below, comprising depending lips formed on said tray, members seated on said lips and bolts carried by said members and threaded into said cover.

6. In a bubble tower having a circular outer wall, in combination, a plurality of spaced bubble trays having bubble openings therein, bubble caps associated with said openings, a downcomer associated with each tray, certain downcomers extending to a point below the liquid level on the tray below, other downcomers terminating above the bubble caps of the tray below, said last downcomers having side cut buckets associated therewith and being interchangeable with said first downcomers whereby a side cut can be taken from anyselected tray after the tower is assembled. Y

7. In a bubble tower having a circular outer wall, in combination, a plurality of spaced bubble t'rays having bubble openings therein, bubble caps associated with said openings, a downcomer associated with each tray, certain downcomers extending to a point below the liquid level on the tray below, other downcomers terminating above the bubble caps of the tray below, said last downcomers having side cut buckets associated therewith and being interchangeable with said first downcomers whereby a side cut can be taken from any selected tray after the tower is assembled, said side cut lbuckets having chambers around said downcomers adapted to receive and store a quantity of liquid, having discharge openings on opposite sides of said downcomer, walls around said openings having overow means associated therewith to discharge liquid to the tray below, and a liquid discharge pipe leading from said bucket to the wall of said tower.

8. In a bubble tower, in combination, an outer circular wall, a plurality of bubble trays-in said tower, vside cut buckets associated with certain selected trays, said wall having tapped holes between said trays, each hole being adapted to receive a connection with the corresponding side cut bucket whereby the location of the side cuts can be changed without altering the exterior of said tower.

RALPH M. PAR'SONS. 

